Cheese & Onion Pasties

I might be remembering wrong, but I think the cheese & onion pasties served at Tea & Sympathy had a creamier sort of cheese sauce than straight melted cheese would accomplish.  Since most recipes I've seen just have melted cheese inside, I've devised my own version to more closely resemble the cheese sauce of Welsh rarebit or a good macaroni and cheese recipe.  The short pastry recipe comes from Alton Brown's recipe for Pocket Pies.

Ingredients
for crust:

9 1/2 ounces all-purpose flour, approximately 2 cups
2 teaspoons baking powder
3/4 teaspoon kosher salt
2 1/2 ounces shortening, approximately 6 tablespoons
3/4 cup milk
1 egg mixed with 1 to 2 teaspoons water

for filling:

1 tablespoons butter

1/4 cup diced onion (yellow or white)
1/3 cup evaporated milk
1/2 teaspoon kosher salt
Fresh black pepper
2 tsp Dijon mustard
1/2 tsp Worcestershire sauce
8 ounces sharp cheddar, shredded

Directions

1. [Steps 1 & 2 can be done up to 2 days in advance and refrigerated.]  Melt butter in a sauce pan over medium heat.  Add diced onions and sweat until translucent.

2. Whisk together evaporated milk, salt, pepper, and mustard.  Add to pan with butter and onions, add shredded cheese, and stir, continuing to cook over low heat until creamy, about 2 minutes.  Set aside and allow to cool completely.

3. In the bowl of a food processor, combine the flour, baking powder and salt. Pulse for a few seconds and then pour into a large mixing bowl.

4. Add the shortening and knead it into the flour with your hands until it is crumbly. Add the milk all at once and mix in with a spatula until it begins to come together. Lightly flour your hands and the countertop and turn the dough out onto the countertop. Knead the dough ball, folding over 10 to 20 times. Using a rolling pin roll the dough to 1/3 to 1/2-inch thickness, then cut into rounds using a 2 1/4-inch ring. Roll each round as thinly as possible or to 5 to 6 inches in diameter. Spoon 1 to 2 tablespoons of filling onto the dough, brush the edges of half of the dough lightly with the egg wash, fold over and seal the edges together with the tines of a fork, dipping it into flour as needed. Gently press down to flatten and evenly distribute the filling. 

5. Preheat the oven to 350 degrees F. Place finished pies onto an ungreased cookie sheet and bake for 25 to 30 minutes or until golden brown.